Crank-case-ventilating system



` R. K. JACK CRANK CASE VENTILATING SYSTEM Filed Aug. 25, 1926 Patented Oct. 2,- 1928.

UNITED STATES PATENT oFFllcE.

ROBERT E Jack, or LANSING, MICHIGAN, AssIGNoR To. GENERAL iuoToRs Conro- `BATION', OF DETROIT, MICHIGAN,

AooRroRATIoN or MICHIGAN.

cRANK-cAsE-VENTILATING sYsTrM.

Application filed August 23, 1926. Serial No. 131,064.

-This is an improvement on the invention disclosed in my prior application 'Serial No. 28,419, filed May 6, 1925. In that application I disclosed a crankcase Ventilating system in which part of the carburetor airsupply is taken from a hot air stove and the remaining part from the crankcase, the air supplied to the crank case to replace that withdrawn being cleaned by passage through an air cleaner.

In this application I have disclosed a similar Ventilating system in which a portion of the air supply after being cleaned in a large commercial type of air cleaner passes directly to the carburetor while the remainder of the f5 air supply is obtained from the crankcase. To prevent dirt from entering the crankcase with the stream passing through to the carburetor I have provided the crankcase air inlet with an air cleaner. This cleaner may be zo of small, capacity and of very simple type for the reason that the major portion of the carburetor air supply is taken through the main air cleaner, in actual practice about twothirds ofthe total. y With this system I have found by actual tests that there is a sucient flow of air through the crankcase to remove the greater proportion of the diluents from the lubricated oil and yet neither the suction a plied to y the crankcase nor the velocity o the air stream flowing through it are sufficiently great to draw appreciable quantities of oil particles into the carburetor. Consequently clogging of the carburetor is avoided. To further insure against the passage of oil particles. from the crankcase into the carburetor I have preferably employed the expedient also made use of in my prior construe-- tion of taking the vaporsy out of the crankcasei 4o by way of the valve chamber so that the valve mechanism acts after the manner of a baffle to intercept particles of oil. `This also insures effective lubrication of the valve mechanism.

In the drawings:

Figure 1 is a side elevation of an engine provided with my Ventilating system.

Figure 2 is a vertical section through the' engine taken substantially on line 2-2 of Figure 1; and

Figure 3 isa section on line 3-3 of Figure 1.

Referenceeharacter 2 indicates an internal combustion engine of conventional type. The engine is.- provided with crankcase 4 which I or the like. While I have describedin'de.-

serves as a lubricant reservoir, with valve` chamber communicating with the crankcase through openings 8 arranged about the valve tappet guides and with carburetor 10 which suppliesfuel mixture to the engine through intake manifold 12.

Part of the carburetor air supply is taken directly from the atmosphere and-the re'- mainder from the crankcase. Thus 14 indicates the carburetor air intake and 16'indi- Cates a fitting having branches 18 and 20. Branch 18 is secured to cover 21 of the valve chamber 6. To branch 16 is secured main air cleaner 22. This cleaner is preferably of the standard commercial type shown and claimed in the application of -I-Ierbert G. Kamrath Serial No. 75,071, iled Dec. 12, 1925. The cleaner draws its supply of air from the stream set in motion in the direction of arrow 24 by the usual cooling fan. Balie 26 is provided so that the air entering the cleaner must make a sharp reverse turn which effectively eliminates the larger particles of dust.` Upon entering the cleaner the air is giveny a spiral motion by means of suitable blades arranged at the forward end of the casing causing dust particles to follow the inner surface of the casing to a discharge port 28, the main air stream reversing in direction and passing out throu h the central' passage 30 connected with 85 brano 20 of fitting 16. If desired an air straightener may be provided in the passage 30 as shown in the said Kamrath application. While I have preferred to indicate a cleaner of thel above type it is to be understood that any other suitable type may be employed.

An auxiliary air cleaner 32 is provided at the crankcaseair inlet 34. This cleaner is of the general type described and claimed in the application of Herbert G. Kamrath,Seri al No. 53,341, filedAug. 29, 1925. For convenience it is vmounted upon the upper end of oil gauge 36. This cleaner comprises a cas-. ing 36 having an open end 38l in which arearranged spiral blades 40. Through the. -f' f posite end of the casing protrudes pipe2 through which air is .discharged intov the crankcase. 'At this end of the casing dust outlet 44 is provided. The end of the oil gauge 36 is secured to the pipe 42 by welding tail a specific type'of cleaner aswell as a I specific mounting for it, it is to be understood that so far as my invention is concerned r any other suitable type of cleaner may besub- 1,10

stituted and the mounting may be varied to suit the convenience of the particular engine. It will now be understood that the engine suction is effective at the carburetor air intake 14 to dranT Vair both directly from the atmosphere and from the crankcase. The main air supply, which s preferably about two-thirds of the total, is cleaned by passage throu h cleaner 22 and in its passage through the tting 16 produces an aspirating effect upon the open end of the conduit 18. To enhance this .aspirating effect I have preferably provide baille 5() which is in effect a continuation of the rear Wall of branch 18. By the'use of this baflle the speed of flow of the main air supply is increased with resultant increase in aspiratingeffect.

Air entering the crankcase through inlet 34 is cleaned by passage through cleaner 32. In the crankcase it is thorougly mixed with the oil and vapors therein so that diluents such as gasolene and water are evaporated and carried along .with the air stream through the valve chamber 6, Where the heat of the cylinder walls serves to maintain the diluents in vapor'form, and through branch 18 of fitting 20 into the carburetor air intake 14. In passing through the valve chamber the heavier particles of oil are intercepted in part by the valve -operating mechanism and serve to effectively lubricate' the latter.

I claim:

1. The combination of an engine provided with a crankcase and a carburetor, a conduit 2. In the combination as defined in claim.

1, an air cleaner for said first named conduit, and anauxiliary air cleaner for said air inlet.

3. The combination of an engine provided with a crankcase and a carburetor, a main air cleaner, a conduit for connecting said cleaner with the carburetor, said crankcase being provided wtli an air inlet, an auxiliary air cleaner for said inlet, and a conduit connecting said crank-fase with the carburetor independently of said au' cleaner, said engine being provided with a valve chamber and said conduit communicating with the cranlrcase through said chamber.

In testimony whereof I aiiix m signature.

` ROBERT JACK. 

